G4, What a grip is used for tennis racket gripping and can be found at walmart, or you can get it on Amazon. Here is a link if you want to buy it online:
http://www.amazon.com/gp/product/B0002SY2A4?ie=UTF8&tag=momsto-20&linkCode=as2&camp=1789&creative=390957&creativeASIN=B0002SY2A4"
It cost less than $3 and many people have raved about it. Its basically a stretch material. I have seen some people use it as part of the hanging wrap, and others as a flaccid wrap. My experience is that its not quite restrictive enough around the glans, and it tends to stretches out quickly. It does not hold my flaccid at the length I would like but this is probably because my flaccid glans really shrinks down to the same size as my shaft, so it cannot use the "barb" effect to keep it on. am sure with your size, it would be a different story though. Keep in mind, I am only have about a FG of 4.5"
I found the larger silicon sleeves works better for me and have the perfect constriction for me. Its good enough to keep my flaccid penis extended, yet not too tight so that I have to check it every 15 minutes to ensure my dick is not going to fall off. The problem is that they are darn near impossible to buy. I had one from a sex kit, but cannot seem to find an inexpensive one at any of the retailer/online stores, by itself. Considering the lifetime was only a couple weeks, I refuse to spend over $20 a shot. I was thinking about going the DIY route in the future.
If anyone is interested in the DIY sleeves, just google "Silicone Sleeves - Make Your Own". I have not tried it yet, but will soon. I originally saw the article on Thunders.